A hybrid continuous glucose and lactate monitor with improved signal reliability Biolinq Inc. (f/k/a Electrozyme LLC) 7. PROJECT SUMMARY Over the past decade, the diabetes community has benefited enormously from the successful commercialization of multiple generations of continuous glucose monitors (CGMs). These devices are able to report readings of glucose in the interstitial fluid (ISF) to users on a near real-time basis. Over the few years, driven primarily by demands for improved glycemic management in insulin-dependent diabetes, the accuracy and reliability of CGM devices made further advances leading to FDA approval of their use in determining insulin dosing without the need for confirmatory fingersticks. The latest generation of CGM devices are routinely used to provide input to automated insulin delivery (AID) systems. However, despite these impressive improvements in CGM technology, CGMs today remain limited to the measurement of a single analyte and lack the ability to take redundant measurements. It is increasingly recognized that further advances in glycemic management will likely require the addition of other circulating biomarkers to elucidate individual variability in glycemic response, especially to physical activity. Measurement of freely circulating lactate can augment established glucose measurements as lactate has been found to shift glycemic thresholds for hypoglycemia in individuals with T1D to lower plasma glucose concentrations [33]. This project thus aims to provide a novel CGM platform capable of accurately measuring both glucose and lactate. We believe that a combined glucose and lactate continuous monitoring system will enhance the safety and efficacy of the next generation of AID systems. Biolinq has developed a body-worn patch containing a microneedle array with multiplexed sensing elements. Clinical studies to date have used a microneedle array consisting of individually-addressable microneedles inserted into the reticular dermis ? approximately 200 to 350 microns below the surface of the skin. Previous work has shown a high level of correlation between glucose in the dermal interstitial fluid and blood glucose [57]. Our clinical studies have confirmed the high level of correlation reported and low lag time previously established for glucose in the dermal ISF [36]; we believe this is a unique property of sensing in the dermis and can be extended to other metabolites. In accordance with the project plan, the research effort seeks to attain the following objectives: (1) development and refinement of a lactate-selective sensing chemistry and its co-location with Biolinq?s clinically-validated glucose-selective chemistry, (2) implementation of redundant measures of glucose and lactate in a microneedle array sensor platform featuring individually-addressable sensing elements to provide accurate and reliable measurements in the dermal ISF, and (3) design of an end-to-end body-worn sensing system containing a miniaturized, low-power application-specific integrated circuit with Bluetooth wireless capability. The technology and business objectives outlined in this proposal will have a direct impact on open- and closed-loop insulin delivery and should meet current needs for an accurate, non-invasive continuous glucose and lactate monitor with broad applicability owing to its enhanced reliability, accuracy, simple use profile, and low-cost nature.